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70. I know it is difficult __________ him to talk like the lecturer, but I think he should grasp every chance .

70. I know it is difficult __________ him to talk like the lecturer, but I think he should grasp every chance .

A. of                      B. for                     C. with                   D. Over

70. I know it is difficult __________ him to talk like the lecturer, but I think he should grasp every chance .